Figure 4

The effect of glutamate receptor antagonists and a glial metabolism inhibitor on the increase of neuronal excitation by picrotoxin. A, Spatially averaged time courses of presynaptic excitation in the substantia gelatinosa of spinal dorsal horn elicited by a high-intensity single-pulse stimulation to the dorsal root in the presence of D-AP5 and CNQX (thin line), and after adding picrotoxin (bold line). B, Spatially averaged time courses of the optical response in the substantia gelatinosa of spinal dorsal horn elicited by a high-intensity single-pulse stimulation to the dorsal root in the presence of D-AP5, CNQX and MFA (thin line), and after adding picrotoxin (bold line). C, The bar graph summarizes the picrotoxin-induced increases in the presynaptic excitation without D-AP5 and CNQX (w/o D-AP5+CNQX) in the presence of D-AP5 and CNQX (D-AP5+CNQX), and presynaptic excitation in the presence of D-AP5, CNQX and MFA (D-AP5+CNQX+MFA) elicited by high-intensity stimulation.